Nodejs Array Every every(isOk)

Method Source Code

const array = [1, 42, 7, 9, 13, 10, 20, 35, 45, -7, -3, 0, 4, -1, 15];

Array.prototype.every = function(isOk) {
  // console.log('Our function is called');
  const len = this.length;
  for(let i = 0; i < len; i += 1) {
    console.log(isOk(this[i], i, this));
    if(!isOk(this[i], i, this)) {
      return false;
    }/*from   w  ww .j a v a 2s  .co  m*/
  }
  return true;
};

Array.prototype.some = function(isOk) {
  //console.log('Our function is called');
  const len = this.length;
  for(let i = 0; i < len; i += 1) {
    if(isOk(this[i], i, this)) {
      return true;
    }
  }
  return false;
};

console.log(array.some(x => x < 10));
console.log(array.some(x => x > 100));
console.log([1,2,3].some(x => x < 10));

function isIncreasing(x, i, arr) {
  if(i === 0) {
    return true;
  }

  return arr[i - 1] < x;
}

console.log([1,2,3].every(isIncreasing));
console.log([42, 1, 2, 3].every((x, i) => x % 2 === i % 2));

Related

1. every(fn, context)

   Array.prototype.every = function(fn, context) {
     if (typeof fn != "function") {
       throw new TypeError(fn + " is not a function");
     if (typeof context === 'undefined') {
       context = this;
     for (var i = 0, l = this.length; i < l; i++) {
       if (this.hasOwnProperty(i) && !fn.call(context, this[i], i, this)) {
   ...
   

2. every(fun /*, thisp */)

   Array.prototype.every = Array.prototype.every || function(fun ) {
     "use strict";
     if (this === void 0 || this === null) throw new TypeError();
     var t = Object(this);
     var len = t.length >>> 0;
     if (typeof fun !== "function") throw new TypeError();
     var thisp = arguments[1];
     for (var i = 0; i < len; i++) {
       if (i in t && !fun.call(thisp, t[i], i, t)) return false;
   ...
   

3. every(fun /*, thisp*/)

   Array.prototype.every = Array.prototype.every || function(fun )  {
       var len = this.length >>> 0;
       if (typeof fun != "function") {
           throw new TypeError();
       var thisp = arguments[1];
       for (var i = 0; i < len; i++) {
           if (i in this &&
               !fun.call(thisp, this[i], i, this)) {
   ...
   

4. every(iterator)

   Array.prototype.every = function(iterator) {
     for (var i = 0, len = this.length; i < len; i++) {
       if (!iterator(this[i], i)) {
         return false;
     return true;
   };
   

5. everySyncasync (callback, thisArg)

   Array.prototype.everySync = async function (callback, thisArg) {
     for (let [index, item] of Object.entries(this)) {
       if (!await callback(item, index, this)) return false
     return true
   

6. every(callback)

   Array.prototype.every = function every(callback) {
     if (typeof callback !== 'function') {
       throw new TypeError(callback + ' is not a function');
     for (var array = this, index = 0, length = array.length; index < length; ++index) {
       if (index in array && !callback.call(arguments[1], array[index], index, array)) {
         return false;
     return true;
   };
   

7. every(callback)

   Array.prototype.every = function every(callback) {
     if (this === undefined || this === null) {
       throw new TypeError(this + 'is not an object');
     if (!(callback instanceof Function)) {
       throw new TypeError(callback + ' is not a function');
     var
     object = Object(this),
   ...